scholarly journals Deep Deterministic Policy Gradient Algorithm Based on Convolutional Block Attention for Autonomous Driving

Symmetry ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1061
Author(s):  
Yanliang Jin ◽  
Qianhong Liu ◽  
Liquan Shen ◽  
Leiji Zhu
Keyword(s):  
Reinforcement Learning ◽  
Supervised Learning ◽  
State Of The Art ◽  
Autonomous Driving ◽  
Attention Mechanism ◽  
Gradient Algorithm ◽  
Excellent Performance ◽  
Average Speed ◽  
The Road ◽  
Policy Gradient

The research on autonomous driving based on deep reinforcement learning algorithms is a research hotspot. Traditional autonomous driving requires human involvement, and the autonomous driving algorithms based on supervised learning must be trained in advance using human experience. To deal with autonomous driving problems, this paper proposes an improved end-to-end deep deterministic policy gradient (DDPG) algorithm based on the convolutional block attention mechanism, and it is called multi-input attention prioritized deep deterministic policy gradient algorithm (MAPDDPG). Both the actor network and the critic network of the model have the same structure with symmetry. Meanwhile, the attention mechanism is introduced to help the vehicles focus on useful environmental information. The experiments are conducted in the open racing car simulator (TORCS)and the results of five experiment runs on the test tracks are averaged to obtain the final result. Compared with the state-of-the-art algorithm, the maximum reward increases from 62,207 to 116,347, and the average speed increases from 135 km/h to 193 km/h, while the number of success episodes to complete a circle increases from 96 to 147. Also, the variance of the distance from the vehicle to the center of the road is compared, and the result indicates that the variance of the DDPG is 0.6 m while that of the MAPDDPG is only 0.2 m. The above results indicate that the proposed MAPDDPG achieves excellent performance.

scholarly journals Deterministic Value-Policy Gradients

2020 ◽  
Vol 34 (04) ◽  
pp. 3316-3323
Author(s):  
Qingpeng Cai ◽  
Ling Pan ◽  
Pingzhong Tang
Keyword(s):  
Reinforcement Learning ◽  
State Of The Art ◽  
Learning Algorithms ◽  
Infinite Horizon ◽  
Gradient Algorithm ◽  
Continuous Control ◽  
Model Bias ◽  
Model Free ◽  
Policy Gradient ◽  
Analytical Gradients

Reinforcement learning algorithms such as the deep deterministic policy gradient algorithm (DDPG) has been widely used in continuous control tasks. However, the model-free DDPG algorithm suffers from high sample complexity. In this paper we consider the deterministic value gradients to improve the sample efficiency of deep reinforcement learning algorithms. Previous works consider deterministic value gradients with the finite horizon, but it is too myopic compared with infinite horizon. We firstly give a theoretical guarantee of the existence of the value gradients in this infinite setting. Based on this theoretical guarantee, we propose a class of the deterministic value gradient algorithm (DVG) with infinite horizon, and different rollout steps of the analytical gradients by the learned model trade off between the variance of the value gradients and the model bias. Furthermore, to better combine the model-based deterministic value gradient estimators with the model-free deterministic policy gradient estimator, we propose the deterministic value-policy gradient (DVPG) algorithm. We finally conduct extensive experiments comparing DVPG with state-of-the-art methods on several standard continuous control benchmarks. Results demonstrate that DVPG substantially outperforms other baselines.

scholarly journals Safe Driving Of Autonomous Vehicles Through Improved Deep Reinforcement Learning

2021 ◽  
Author(s):  
Abhishek Gupta
Keyword(s):  
Reinforcement Learning ◽  
Object Detection ◽  
Autonomous Vehicles ◽  
Autonomous Driving ◽  
Safe Driving ◽  
The Road ◽  
Reward Function ◽  
Continuous State ◽  
Value Loss ◽  
Policy Gradient

In this thesis, we propose an environment perception framework for autonomous driving using deep reinforcement learning (DRL) that exhibits learning in autonomous vehicles under complex interactions with the environment, without being explicitly trained on driving datasets. Unlike existing techniques, our proposed technique takes the learning loss into account under deterministic as well as stochastic policy gradient. We apply DRL to object detection and safe navigation while enhancing a self-driving vehicle’s ability to discern meaningful information from surrounding data. For efficient environmental perception and object detection, various Q-learning based methods have been proposed in the literature. Unlike other works, this thesis proposes a collaborative deterministic as well as stochastic policy gradient based on DRL. Our technique is a combination of variational autoencoder (VAE), deep deterministic policy gradient (DDPG), and soft actor-critic (SAC) that adequately trains a self-driving vehicle. In this work, we focus on uninterrupted and reasonably safe autonomous driving without colliding with an obstacle or steering off the track. We propose a collaborative framework that utilizes best features of VAE, DDPG, and SAC and models autonomous driving as partly stochastic and partly deterministic policy gradient problem in continuous action space, and continuous state space. To ensure that the vehicle traverses the road over a considerable period of time, we employ a reward-penalty based system where a higher negative penalty is associated with an unfavourable action and a comparatively lower positive reward is awarded for favourable actions. We also examine the variations in policy loss, value loss, reward function, and cumulative reward for ‘VAE+DDPG’ and ‘VAE+SAC’ over the learning process.

scholarly journals Safe Driving Of Autonomous Vehicles Through Improved Deep Reinforcement Learning

2021 ◽  
Author(s):  
Abhishek Gupta
Keyword(s):  
Reinforcement Learning ◽  
Object Detection ◽  
Autonomous Vehicles ◽  
Autonomous Driving ◽  
Safe Driving ◽  
The Road ◽  
Reward Function ◽  
Continuous State ◽  
Value Loss ◽  
Policy Gradient

In this thesis, we propose an environment perception framework for autonomous driving using deep reinforcement learning (DRL) that exhibits learning in autonomous vehicles under complex interactions with the environment, without being explicitly trained on driving datasets. Unlike existing techniques, our proposed technique takes the learning loss into account under deterministic as well as stochastic policy gradient. We apply DRL to object detection and safe navigation while enhancing a self-driving vehicle’s ability to discern meaningful information from surrounding data. For efficient environmental perception and object detection, various Q-learning based methods have been proposed in the literature. Unlike other works, this thesis proposes a collaborative deterministic as well as stochastic policy gradient based on DRL. Our technique is a combination of variational autoencoder (VAE), deep deterministic policy gradient (DDPG), and soft actor-critic (SAC) that adequately trains a self-driving vehicle. In this work, we focus on uninterrupted and reasonably safe autonomous driving without colliding with an obstacle or steering off the track. We propose a collaborative framework that utilizes best features of VAE, DDPG, and SAC and models autonomous driving as partly stochastic and partly deterministic policy gradient problem in continuous action space, and continuous state space. To ensure that the vehicle traverses the road over a considerable period of time, we employ a reward-penalty based system where a higher negative penalty is associated with an unfavourable action and a comparatively lower positive reward is awarded for favourable actions. We also examine the variations in policy loss, value loss, reward function, and cumulative reward for ‘VAE+DDPG’ and ‘VAE+SAC’ over the learning process.

scholarly journals Toward Self-Driving Bicycles Using State-of-the-Art Deep Reinforcement Learning Algorithms

Symmetry ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 290 ◽  
Author(s):  
SeungYoon Choi ◽  
Tuyen Le ◽  
Quang Nguyen ◽  
Md Layek ◽  
SeungGwan Lee ◽  
...  
Keyword(s):  
Reinforcement Learning ◽  
Deep Neural Network ◽  
Learning Algorithm ◽  
State Of The Art ◽  
The Other ◽  
Gradient Algorithm ◽  
Reward Function ◽  
Policy Gradient ◽  
Policy Optimization ◽  
Start Location

In this paper, we propose a controller for a bicycle using the DDPG (Deep Deterministic Policy Gradient) algorithm, which is a state-of-the-art deep reinforcement learning algorithm. We use a reward function and a deep neural network to build the controller. By using the proposed controller, a bicycle can not only be stably balanced but also travel to any specified location. We confirm that the controller with DDPG shows better performance than the other baselines such as Normalized Advantage Function (NAF) and Proximal Policy Optimization (PPO). For the performance evaluation, we implemented the proposed algorithm in various settings such as fixed and random speed, start location, and destination location.

scholarly journals Learning 2-Opt Heuristics for Routing Problems via Deep Reinforcement Learning

2021 ◽  
Vol 2 (5) ◽  
Author(s):  
Paulo da Costa ◽  
Jason Rhuggenaath ◽  
Yingqian Zhang ◽  
Alp Akcay ◽  
Uzay Kaymak
Keyword(s):  
Deep Learning ◽  
Reinforcement Learning ◽  
State Of The Art ◽  
Gradient Algorithm ◽  
Routing Problems ◽  
Routing Problem ◽  
Local Search Heuristic ◽  
Policy Gradient ◽  
Previous State ◽  
The Traveling Salesman Problem

AbstractRecent works using deep learning to solve routing problems such as the traveling salesman problem (TSP) have focused on learning construction heuristics. Such approaches find good quality solutions but require additional procedures such as beam search and sampling to improve solutions and achieve state-of-the-art performance. However, few studies have focused on improvement heuristics, where a given solution is improved until reaching a near-optimal one. In this work, we propose to learn a local search heuristic based on 2-opt operators via deep reinforcement learning. We propose a policy gradient algorithm to learn a stochastic policy that selects 2-opt operations given a current solution. Moreover, we introduce a policy neural network that leverages a pointing attention mechanism, which can be easily extended to more general k-opt moves. Our results show that the learned policies can improve even over random initial solutions and approach near-optimal solutions faster than previous state-of-the-art deep learning methods for the TSP. We also show we can adapt the proposed method to two extensions of the TSP: the multiple TSP and the Vehicle Routing Problem, achieving results on par with classical heuristics and learned methods.

Preceding vehicle following algorithm with human driving characteristics

2021 ◽  
pp. 095440702098154
Author(s):  
Feng Pan ◽  
Hong Bao
Keyword(s):  
Reinforcement Learning ◽  
Weight Vector ◽  
Gradient Algorithm ◽  
Inner Product ◽  
Inverse Reinforcement Learning ◽  
Reward Function ◽  
Human Driver ◽  
Policy Gradient ◽  
Preceding Vehicle ◽  
Action Spaces

This paper proposes a new approach of using reinforcement learning (RL) to train an agent to perform the task of vehicle following with human driving characteristics. We refer to the ideal of inverse reinforcement learning to design the reward function of the RL model. The factors that need to be weighed in vehicle following were vectorized into reward vectors, and the reward function was defined as the inner product of the reward vector and weights. Driving data of human drivers was collected and analyzed to obtain the true reward function. The RL model was trained with the deterministic policy gradient algorithm because the state and action spaces are continuous. We adjusted the weight vector of the reward function so that the value vector of the RL model could continuously approach that of a human driver. After dozens of rounds of training, we selected the policy with the nearest value vector to that of a human driver and tested it in the PanoSim simulation environment. The results showed the desired performance for the task of an agent following the preceding vehicle safely and smoothly.

scholarly journals I4R: Promoting Deep Reinforcement Learning by the Indicator for Expressive Representations

2020 ◽  
Author(s):  
Xufang Luo ◽  
Qi Meng ◽  
Di He ◽  
Wei Chen ◽  
Yunhong Wang
Keyword(s):  
Reinforcement Learning ◽  
Supervised Learning ◽  
Singular Values ◽  
Regularization Term ◽  
Policy Gradient

Learning expressive representations is always crucial for well-performed policies in deep reinforcement learning (DRL). Different from supervised learning, in DRL, accurate targets are not always available, and some inputs with different actions only have tiny differences, which stimulates the demand for learning expressive representations. In this paper, firstly, we empirically compare the representations of DRL models with different performances. We observe that the representations of a better state extractor (SE) are more scattered than a worse one when they are visualized. Thus, we investigate the singular values of representation matrix, and find that, better SEs always correspond to smaller differences among these singular values. Next, based on such observations, we define an indicator of the representations for DRL model, which is the Number of Significant Singular Values (NSSV) of a representation matrix. Then, we propose I4R algorithm, to improve DRL algorithms by adding the corresponding regularization term to enhance the NSSV. Finally, we apply I4R to both policy gradient and value based algorithms on Atari games, and the results show the superiority of our proposed method.

scholarly journals Robust Multi-Agent Reinforcement Learning via Minimax Deep Deterministic Policy Gradient

2019 ◽  
Vol 33 ◽  
pp. 4213-4220 ◽  
Author(s):  
Shihui Li ◽  
Yi Wu ◽  
Xinyue Cui ◽  
Honghua Dong ◽  
Fei Fang ◽  
...  
Keyword(s):  
Reinforcement Learning ◽  
Gradient Algorithm ◽  
Training Environment ◽  
Local Optima ◽  
Continuous Action ◽  
Agent Learning ◽  
Policy Gradient ◽  
Multi Agent ◽  
Continuous Actions ◽  
Computational Intractability

Despite the recent advances of deep reinforcement learning (DRL), agents trained by DRL tend to be brittle and sensitive to the training environment, especially in the multi-agent scenarios. In the multi-agent setting, a DRL agent’s policy can easily get stuck in a poor local optima w.r.t. its training partners – the learned policy may be only locally optimal to other agents’ current policies. In this paper, we focus on the problem of training robust DRL agents with continuous actions in the multi-agent learning setting so that the trained agents can still generalize when its opponents’ policies alter. To tackle this problem, we proposed a new algorithm, MiniMax Multi-agent Deep Deterministic Policy Gradient (M3DDPG) with the following contributions: (1) we introduce a minimax extension of the popular multi-agent deep deterministic policy gradient algorithm (MADDPG), for robust policy learning; (2) since the continuous action space leads to computational intractability in our minimax learning objective, we propose Multi-Agent Adversarial Learning (MAAL) to efficiently solve our proposed formulation. We empirically evaluate our M3DDPG algorithm in four mixed cooperative and competitive multi-agent environments and the agents trained by our method significantly outperforms existing baselines.

scholarly journals An Actor-Critic-Attention Mechanism for Deep Reinforcement Learning in Multi-view Environments

2019 ◽  
Author(s):  
Elaheh Barati ◽  
Xuewen Chen
Keyword(s):  
Reinforcement Learning ◽  
State Of The Art ◽  
Attention Mechanism ◽  
Feature Representation ◽  
Decision Making Process ◽  
Multiple Views ◽  
Single Feature ◽  
3D Environments ◽  
Noisy Conditions ◽  
Level Of Importance

In reinforcement learning algorithms, leveraging multiple views of the environment can improve the learning of complicated policies. In multi-view environments, due to the fact that the views may frequently suffer from partial observability, their level of importance are often different. In this paper, we propose a deep reinforcement learning method and an attention mechanism in a multi-view environment. Each view can provide various representative information about the environment. Through our attention mechanism, our method generates a single feature representation of environment given its multiple views. It learns a policy to dynamically attend to each view based on its importance in the decision-making process. Through experiments, we show that our method outperforms its state-of-the-art baselines on TORCS racing car simulator and three other complex 3D environments with obstacles. We also provide experimental results to evaluate the performance of our method on noisy conditions and partial observation settings.

scholarly journals The Successful Ingredients of Policy Gradient Algorithms

2021 ◽  
Author(s):  
Sven Gronauer ◽  
Martin Gottwald ◽  
Klaus Diepold
Keyword(s):  
Reinforcement Learning ◽  
State Of The Art ◽  
Gradient Methods ◽  
Gradient Algorithms ◽  
The Sublime ◽  
Policy Gradient ◽  
Art Performance ◽  
Underlying Mechanisms

Despite the sublime success in recent years, the underlying mechanisms powering the advances of reinforcement learning are yet poorly understood. In this paper, we identify these mechanisms - which we call ingredients - in on-policy policy gradient methods and empirically determine their impact on the learning. To allow an equitable assessment, we conduct our experiments based on a unified and modular implementation. Our results underline the significance of recent algorithmic advances and demonstrate that reaching state-of-the-art performance may not need sophisticated algorithms but can also be accomplished by the combination of a few simple ingredients.

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